I would say that was really about bad luck. You were ahead on virtually all positions, so the Take it Easy-Attitude cost you the few missed shots that lost you the game in the end. But those upsets happen, otherwise it wouldn't be a fun game.
I don't agree with Hassan in two points, first with the free throw problems (when taking 7 FTs) and about the choice of tactics. The opponent didn't have a clear weak point, aside from his SF. The Base Offense seems like a pretty reasonable solution against such an opponent.
Cheers, Exos